By now the fact that climate change is a global environmental, social and economic threat comes as a surprise to few. Many world leaders even call climate change the single greatest threat to humanity in this century. Latin American cities are particularly vulnerable to the devastating effects of climate change.

By now the fact that climate change is a global environmental, social and economic threat comes as a surprise to few. Many world leaders even call climate change the single greatest threat to humanity in this century. Climbing global temperatures are predicted to cause sea level rise, more frequent extreme weather events such as flooding, droughts, and storms, and increases in the spread of tropical diseases. It's also a widely-known fact that reducing global carbon emissions is key to mitigating climate change. But what may come as a surprise to some is that cities are responsible for a whopping 75% of global CO2 emissions - with transportation and buildings serving as the largest contributors. Considering that climate change has such devastating effects on urban life, it is critical that cities take leadership of climate change mitigation by reducing carbon emissions and creating sustainable, resilient communities starting now.

Latin American cities are particularly vulnerable to the devastating effects of climate change. Not only is the region comprised of still-developing countries with fragile economies, it also happens to be the most urbanized region in the world with 80 percent of its inhabitants living in cities. The rampant inequality present in many of Latin America's cities leaves this region's low-income communities particularly vulnerable to the impacts of climate change. Already, these cities are dealing with destructive floods, droughts, deforestation, and health problems from air pollution. Without mitigation, these occurrences will only intensify and increase over time and disproportionality affect low-income residents the hardest. For this reason, cities represent the single greatest opportunity for targeted, meaningful actions that create impact on the ground. Luckily, many cities in the region have already begun taking steps in the right direction by enacting measures to reduce emissions, modernize transportation systems, improve air quality, and invest in clean energy sources.

Bogotá, the capital city of Colombia, is just one of several cities in Latin America that has proven just how effective and important city-wide initiatives can be. With one of the largest inequality gaps in Colombia, the city benefits from initiatives that not only target climate change mitigation and adaptation but also seek to eradicate the inequality that sits at the tangent of many social problems. While the following list is neither comprehensive nor exhaustive, it highlights examples of actions Latin American cities can take to improve the quality of life for millions of people and reduce the risks of climate change based on the experience of the city of Bogotá.

1) Modernize Infrastructure

With transportation and buildings serving as the largest source of CO2 emissions in cities, modernizing infrastructure is a critical area cities should focus on. After more than a decade of exemplary improvements to their privately run bus industry, Bogotá has emerged as a global leader in low-emissions development. The city began tackling its congestion and air pollution problems in 2000 with the introduction of a bus rapid transit (BRT) system known as TransMilenio. Today, over 2,000 of the 18,000 buses operating in the city are part of the BRT network running on a system of 87km and carrying some 1.5 million passengers per day. Since its implementation, TransMilenio has reduced traveling time 32 percent, reduced gas emissions 40 percent and reduced accidents 90 percent. The city was recently awarded funding to begin implementation of its Transit-Oriented Development (TOD) Nationally Appropriate Mitigation Action (NAMA) which boasts not only transportation-driven benefits but promises "co-benefits in the areas of quality-of-life, economic development, social equity, preservation of natural habitat, and energy independence. Individuals will enjoy better neighborhoods, lower costs of transportation and less pollution." The BRT is a perfect example of how cities can address environmental and social goals in tandem.

2) Invest in innovative solutions

Since the late eighties, a massive landfill site plagued the city of Bogotá with health problems from exposure to toxic chemicals, water and air pollution and a slew of additional environmental problems. In 2007, the city turned it into a landfill gas-to-energy project known as the Doña Juana Landfill project which collects, processes and uses the gas generated at the landfill through a process known as landfill gas capture. Once the gas is captured and flared, it is utilized for energy production in nearby industries. The landfill is used for the disposal of around 2 million tons of municipal solid waste generated by the 7.3m inhabitants of Bogotá each year. Though still in progress, the project is expected to reduce emissions in the city by 14.8m tons of CO2 equivalent by the time of its completion around 2024.

3) Focus on city-wide initiatives

While Bogotá counts on support from the national government for many climate change mitigation and adaptation initiatives, not all countries are blessed with a robust political environment conducive to these types of initiatives. But it is not necessary for cities to wait on federal governments to begin to take action. This March for example, Mayor of Bogotá, Gustavo Petro Urrego, announced a set of goals intended to prepare the city for climate change in the next 35 years. He announced the city will work to reduce 20 percent of CO2 emissions from deforestation, fossil fuels and electricity use by 2020 and produce 25 percent of its energy from alternative energy source by 2050. The city is also launching a public awareness campaign that will educate citizens on the effects of climate change and teach them ways to create more sustainable communities. Urrego also established an annual no-car day to coincide with global Earth Day that prohibits personal vehicle and motorcycle usage from 5am to 7:30pm in the entire city in an effort to raise awareness on alternative transportation methods.

Latin America is critical to solving global climate change and while individual countries are taking bold steps to tackle the problem, it is crucial for rapidly urbanizing cities to pave the way for change starting now and act as blueprints for others moving forward. The decisions made today will shape how the cities of tomorrow operate and how well they adapt to the pressures and challenges of a changing climate.